A low-dropout (LDO) voltage regulator is a DC linear voltage regulator that is capable of regulating an output voltage even when the supply voltage is near the output voltage. Advantages of an LDO regulator over other DC-to-DC regulators include the absence of switching, smaller size, and design simplicity.
A capacitor-less low-dropout (CL-LDO) voltage regulator corresponds to a LDO voltage regulator that does not require an off-chip capacitor to achieve stability. Advantages of a CL-LDO regulator over conventional LDO regulators include the lower number of external components and PCB area thereby reducing total cost of the system.
In some applications, an LDO regulator may be used to regulate a voltage applied to the logic gates of a Sea-of-Gates (SoG). In those cases, CL-LDOs regulator solutions may be desired in order to lower total cost of the system.
Therefore, the inventors hereof have recognized a need for a capacitor-less LDO regulator for logic circuits with improved transient performance and power-efficiency while supporting a wide load current range. An SoG load profile includes a dynamic current resulting from logic switching activity (fast-speed), and a leakage current that is mainly dependent on operating temperature (slow-speed). The leakage component can range from a negligible value at low temperatures to values several times higher than the dynamic component at high temperatures. Furthermore, low-power operation modes that employ power and/or clock-gating techniques can also extend the load range requirements in a way that conventional LDO regulators cannot satisfy.